Shock absorber



SHOCK ABSORBER Filed May ll, 1951 2 Sheets-Sheet l.

INV-ENTOR AT-roRNEYS A THOMSON April 5, 1932.

SHOCK ABSORBER 2 Sheets-Sheet 2 Filed May l1, 1931 INVENTOR ATTORN ELS Patented pr. 5', 1932 sHocK Ansonnnn p Appucation mea May 11,1931. seriai Np. 536,391.

The present invention pertains to a novel shock absorber designed particularly for use in connection with motor vehicles.

The principal object of the invention is to provide a device of this character which functions to 4absorb or cushion the recoil or rebound action of a vehicle spring after the latter has been compressed. The device moreover is substantially inactive while the vehiiccle spring moves from normal position into full compression.

More particularly, the device is constructed to exert its greatest braking or shock absorbing action at the beginning of the recoil moveif. ment and to diminish this action as the recoilmovement continues to its end. Thus, the maximum braking action is available when most necessary and, by its gradually decreasing effectiveness, avoids an abrupt check or au stoppage of the recoil movement while eiectively cushioning this movement in a manner not detrimental to the comfort of the passengers in the vehicle.

The invention is fully disclosed by way of example in the following description and in the accompanying drawings, in which- Figure 1 is a vertical cross section of the device, on the line 1-1 of Figure 2;

Fig. 2 is a longitudinal section on the line 2-2 of Figure 1;

Fig. 3 is a section on the line 3--3 of Figure 1;

Fig. .4 is a fragmentary perspective view of the operating arm; Y Figs. 5 and 6 are sections on the lines 5-5 and 6-6 respectively of Figure 2; y

Fig. 7 is a section on the line 7-7 of Figure 1; and

Fig. 8 is a detail side elevation of a motor vehicle showing the device applied thereto.

Reference to these views will now 'be made by use of like characters which are employed of integral lugs 5, whereby the stud is locked against rotation. The various parts of the mechanism are confined in a casing 6 rotatably mounted on the stud. y f

The device is operated through an operating arm 7 which hasal boss 8 rotatably mounted on the body of the stud 4 and formed with a projecting lug or key 9 `for a purpose which will presently be described. The free end of the arm 7 is articulated to a 60 `link 10 whichin turn is pivoted to a clamp An arm 14 is rotatably mounted onthel stud 2 by means of anintegral boss 15 which surrounds the stud'as shown more clearly .in 70 Figure 5. The boss has a slot 16 receiving the key 9 as shown inthe same figure, wherebythe arm 14is locked to the arm 7. The stud 2 has another polygonal portion 17 near its outerA end for retaining a non-rotatable ring 18 having a joint'nger 19 extending therefrom for a purpose which will presently appear. i

In one end of the casing is mounted a pair of .primary friction' shoes 20 and V21 in con- 80 tact with each other at one 'endand spaced apart at the other end as shown in Figure 6.

A cam lever 22 is pivotally attached tothe arm 14 by a pin 23, as shown in Figure. 6, and has its free end receivedin the space be- 35 tweenthe shoes 20 and 21. Th-e tree end of the member 21 is in the form of an'inwardextension 24 engaged by the free end of the cam 22 which also receives thefree end of the member 20. The relation of these three contacting parts is such that `a counterclockwise swinging ymovement of the arm 14 rocks the end of the cam lever 22 on the extension V24, y whereby the cam lever` spreads the shoes 2,0

land 21 into firm engagement with ythe cylindrical wallet th-e casing 6. 1` v Located preferably vat the opposite endof the casing 6 is a pair of secondary shoes 25 Y and 26` also engaging the cylindrical wall of 100 the casing 6, in Contact with each other at :one end and spaced apart at the other end.

The free end of the shoe 25 is forked at 27 and receives the tongue or finger 19. To the contacting end of the shoe 26 is pivotally mounted a curved rod 28 extending alongside the shoe 26 substantially as far as the bifur Y cated end 27. A toggle lever 29 hasy one of its ends 30 bearing against the pivoted end of the rod 28, while the other end is forked at 31 to receive the free end of the rod 28' as shown more clearly in Figure 2. Aspiring- 32 surrounds the rod 28 between the arm 14 and forked end 31 and is so adjusted as to exert rio-pressure against either of these -of the spring 32. 'The other end of the Vsfilareading or prying lever 34 has its free end 35v received inthe space betwe-en the ends of the shoes 25 and 26 as shown in Figure 1. Thi's'end is shaped to engage the fork 27 and the freeend ofthe shoe 26 as also shown in Figure 1. i

The casing' 6 is finally closed by ay cover plate 36, and the various parts' assembled on the stud 2 are held together by La nut 37 on onel end of thel stud, the other end being headed as at 38. K 1When lever 14, locked to lever 7 by means Vof the key 9, is in the normal or' non-functioning position, the spring 32is fully` distended uponv its supporting 'rod 28 and exerts little or no pressure 'upon the outer end 31 of `the toggle lever 29.

als

When, however, lever 7 is rotated -i'n a kkclockwise-fdire'ction' by Compression of spring uporitlie 'frame 15, lever 14 isfsimilarly rotated and the;l springl32 is compressed, thereby verert'ing upon-the freev 'end 310i lever 29 a pressure, Vproportionateto the extent of the compression or shock. At the 'same time the one-way or free-wheelfclutch members 20, 21 and 22 are rotated in their free-wheeling -or releasing direction Aand therebyy potenofthe lever 34 spreads the secondaryjshoes 125 -and v26a-.rid places them under' initial tension or pressure against the casing'. The

articulation of the finger 19 in the fork 27 permits variation in the frictio-nal engagement between the shoe 25 and the casing 6, while preventing both shoes 25 and 26 from turning around the stud 2.

On the recoil of the spring 13, the relative movement of the arm 14 is connterclookwise due to the movements of the link 10 and arm 7. The corresponding pull on the cani lever 22 through the pin 23, spreads the primary shoes 2()l-` and 21 against the casing'', whereby the casing is forced to rotate due to the clutch action and its rotatable mounting on the stud 2. Thisturning of the casing, however, is resisted by the initial frictional engagement of the secondary shoes 25 and 2G therewith,

'and this resistance results in retardation or cushioning of the recoil, inasmuch as the shoes 25 and 25 are heid against-,rotation by inea-ns of the finger 19.

Ars-'the recoil movement continues, although retarded, the prying action ofthe cam lever 22 continues until lever 7 completes its inovement, so that the primary shoes 2O and 21 are held iirnily aga-inst the casing 6. During this movement, the arm 14 recedes from the forked end 31'of the toggle lever 29, .vhereupon the pressure of the spring 32 is lessened andthe pressure of the secondary shoes 25 4and 26 against the vcasing 6 is correspond- 'countei'clockwise vso that thev slippage' will occur at the shoes 25 and 26 rather than at the shoes 20' and 21, whereby the diminishing braking action of the shoes 25 and 26 is neverthelessbeing utilized.

The grip of the primary shoes As spring 13l recoils from its compressionl the frame 1 is raised and lever 7 isi thereby rotated in a counterclockwise direction and the free-wheel clutch members20, )'21 and 22 actin-g in their locking or hoidinig direction rotate the casing 6 likewise in a counter-Y 'clockwise direction.Y The free wheel clutch members 20, 21 and 22 do not release until the lever 7 is again rotated in a clockwise direction, when they do release instantaneously.

'Simultaneously with the recoil of spring 13, countercloclwise rotation oflever 14 gradually sl'aclrens the braking pressure of the secondary shoes 25 and 26 on the casing 6 by 'gradual expansion of the spring 32. Y

VAlthough a specific embodiment Vof the invention has been illustrated and described, ift will be understood that Yvariousfalterations in the details of construction may `be vmade without departing fromthe scope of th invent-ion, as indicated by vthe vappended claims. Vhat I claim is: y v t l. A shock absorber 'comprising a stud, a

casing rotatable'tlereon, (an arm 'rotatable 0n said stud and adapted for connection to a spring of a vehicle, a pair of primary friction shoes engaging said casing, spreading means operable on said shoes by movement of said arm in one direction, a pair of secondary friction shoes engaging said casing, means holding said secondary shoes against lrotation relatively to said stud, and spring means normally holding said secondary shoes against said casing.

2. A shock absorber comprising a stud, a casing rotatable thereon, an arm rotatable on said stud and adapted for connection to a spring of a vehicle, a pair of primary friction shoes engaging said casing, spreading means operable on said shoes by movement of said arm in one direction, a pair of secondary friction shoes engaging said casing, means holding saidsecondary shoes against rotation relatively to said stud, spring means normally holding said secondary shoes against said casing, and means for proportioning the pressure of said secondary shoes aga-inst said casing by movement of said arm in said direction.

3. A shock absorber comprising a stud, a casing rotatable thereon, an arm rotatable on said stud and adapted for connection to a spring of a vehicle, a pair of primary friction shoes engaging said casing, another arm fixed to the first arm, acam lever connected to the second arm and inserted between said shoes to spread the latter against said casing by movement of the second arm in one direction, a pair of secondary friction shoes engaging said casing, means holding said secondary shoes against rotation relatively to the lirst arm, and spring means functionally proportioning the pressure of said secondary shoes against said casing.

4. A shock absorber comprising a stud, a casing rotatable thereon, an arm rotatable on said stud and adapted for connection to a spring of a vehicle, a pair of primary friction shoes engaging said casing, another arm fixed to the first arm, a cam lever connected to the second arm and inserted between said shoes to spread the latter against said casing by movement of the second arm in one direction, a pair of secondary friction shoes engaging said casing, means holding said secondary shoes against rotation relatively to the first arm, spring means functionally proportioning the pressure of said secondary shoes against said casing, and means for increasing the pressure of said secondary shoes against said casing by movement of said arm in said direction.

5. A shock absorber comprising a stud, a casing rotatable thereon, an arm rotatable on said stud and adapted for connection to a spring of a vehicle, a pair of primary friction shoes engaging said casing, spreading means operable on said shoes by movement of said arm in one direction, a pair of secondary friction shoes engaging said casing, means holding said secondaryV shoes against rotation relatively to said stud, a prying lever having one end inserted between said sec- :ondary shoes, a toggle lever pivotally mounted upon `saidprying lever, and fulcrumed upon one of thevsecondary friction shoes, and a spring slidably mounted and engag Aing the free fend ofv said toggle lever, to functionally proportion the frictional engagement of the secondary shoes with said casing. Y Y

6. A shock absorber comprising a stud, a casing rotatable thereon, an varm rotatable on said stud and adapted for Vconnection to a spring of a vehicle, a pair of primary friction shoes engaging said casing, spreading means operable on said shoes by movement of said arm in one direction, a pair of secondary friction shoes engaging said casing,

incr

b, n n y 0 of said secondary shoes against said casing by movement of said secondary prying lever in said direction.

7. A shock absorber comprising a stud, a casing rotatable thereon, an arm rotatable on said stud and adapted for connection to a spring of a vehicle, a pair of primary friction shoes engaging said casing, another arm fixed to the first arm, a cam lever connected to the second arm and inserted between saidv shoes to spread the latter against said casing by movement of the second arm in one direction, a pair of secondary friction shoes engaging said casing, means holding said secondary shoes against rotation relatively to the lirst arm, a prying lever having one end inserted between said secondary Ashoes and a spring Aslidably mounted having one end bearing against said second arm and the .other end active upon said secondary prying lever to hold the secondary shoes functionally in frictional engagement with said casing, and means for proportioning the pressure of said secondary shoes against said casing by movement of said arm in said direction.

8. A shock absorber comprising a stud, a casing rotatable thereon, an arm rotatable on said stud and adapted for connection to a spring of a vehicle, a pairof primary friction shoes engaging said casing, another arm fixed to the first arm, a cam lever connected to the second arm and inserted between said shoes to spread the latter againstsaid casing bymovement of the second arm in one direction, a pair' of secondary frictiony shoes engaging said casing, means holdingsaid secondary shoes against rotation relatively to 5 the'rst arm, a prying lever having one end inserted between said secondary shoes, atog g1el'ever pivotally mounted upon said prying Vlever and kful'crumed on one of saidsecondary shoes,fand spring mounted between said second arm and the free end of said toggle' lever, whereby to spread said secondary shoes against said casing .through said prying leven.

9.` A shock absorbervcomprising a stud, a f5 casing rotatable thereon, an arm rotatable on said studkandf adapted for connection t0 a spring of a vehicle, a one-'way clutch fitted Vinto said cas-ing and comprised of a pair of primary friction shoes engaging said cas-' g; ing', together with leverage spreading means operable upon said shoes by movement of said arm in one directiorn' a secondary 0ne way clutch engaging said casing and having friction shoes anchored agaist rotation rela- Y 325 tive tosaid stud, and 'spring means functionallyproportioning the pressure of said secondary shoes against said casing.

In testimony whereof I aiiix my signature. Y

ARTHUR THOMSON. 

